Biomedical subjects

M Bugge

Publications and source records attributed to M Bugge.

At least 37 records · Page 2Linked to original sources

PubMed1997

Gender and diurnal effects on specific open-field behavioral patterns in the portacaval shunted rat.

Hepatic encephalopathy (HE) is a frequently observed neuropsychiatric syndrome with unknown pathogenesis in patients suffering from chronic liver failure. The portacaval shunted (PCS) rat has been extensively used as an experimental model for HE and for studying the effects of portal-systemic shunting. Previous behavioral studies on PCS rats have shown a number of abnormalities but there is no consensus about which abnormalities are characteristic. We therefore made a thorough descriptive study of 100 male and female PCS rats and sham-operated controls four to six weeks after the shunting procedure in an open field. The frequency, duration and average time sequence of various kinds of defined spontaneous behavioral patterns were investigated during both night and day in order to assess behavioral differences between PCS rats and sham-operated controls. The results indicate differences especially regarding motor exploratory behaviors such as forward locomotion and rearing. There were also differences in eating and sniffing behaviors. Our results show that the overall behavioral alteration seen in PCS rats compared to sham-operated controls is that of hypoactivity.

Animals↗

PubMed1997

A large family with subtelomeric translocation t(18;21)(q23;q22.1) and molecular breakpoint in the Down syndrome critical region.

We describe a 17-month-old infant with clinical features of Down syndrome and a normal karyotype by standard chromosomal analysis, her two uncles aged 28 and 30 years, respectively, with reduced intelligence and unusual appearance but not apparent Down syndrome, and a severely retarded 6-year-old girl with dysmorphy and epilepsy from the same family. Cytogenetic studies of patients and normal intervening relatives had been carried out at different institutions with normal results. Fluorescence in situ hybridization using whole chromosome painting and unique-copy probes (cosmids) and high-resolution banding revealed a familial subtelomeric translocation of chromosomes 18 and 21, resulting in partial trisomy 21 in the infant and her two uncles, and partial monosomy 21 in the 6-year-old girl. Cytogenetic breakpoints were located in bands 18q23 and 21q22.1, respectively. The molecular breakpoint on chromosome 21 was located between D21S211 (proximal) and D21S1283 (distal) and thus maps within the Down syndrome critical region.

Adult↗

PubMed1997

The de-airing clamp in cardiac surgery.

De-airing of the heart in open heart surgery is a necessary routine. Most of the air is evacuated from the heart before the aortic cross clamp is removed, but the de-airing may be continued even after declamping. One way to continue de-airing is to partially clamp the ascending aorta, proximally to the aortic cannula, in order to create a pocket for trapping residual air coming from the left ventricle. This paper describes a clamp specially designed and developed for this purpose. It has been used in our center since 1990 and our experience is reported. The clamp has been used on 250 patients and in 50% ultrasonography has been used to examine the heart being free from air bubbles within 20 min from releasing the aortic cross clamp.

Cardiac Surgical Procedures↗

PubMed1997

A patient with Edwards syndrome caused by a rare pseudodicentric chromosome 18 of paternal origin.

We present an unusual case of trisomy 18 due to a pseudodicentric chromosome 18 of paternal origin. The karyotype was: 46,XY, -18, +psu dic(18)(qter-->cen-->p11.31::p11.31-->psucen-->qter). The origin of the abnormal chromosome was verified by FISH with a painting probe from chromosome 18. Absence of short-arm telomeres was shown by multicolor FISH, and the results of DNA analysis showed monosomy for loci D18S59 and D18S170 as well as paternal inheritance of the aberrant chromosome. The child's phenotype was characteristic of trisomy 18.

Centromere↗

PubMed1996

Direct sequencing of PCR products derived from cDNAs for the pro alpha 1 and pro alpha 2 chains of type I procollagen as a screening method to detect mutations in patients with osteogenesis imperfecta.

More than 150 mutations in the genes for type I procollagen have been found in unrelated patients with osteogenesis imperfecta (OI), but mutations have been difficult to define in many patients with the mildest forms of the disease. Here, we have used robotically automated sequencing of the cDNAs for type I procollagen to screen for mutations in 12 patients suspected of having nonlethal OI (types I, III, and IV). Single base mutations that changed codons for obligate glycine residues were found in seven of the patients. Altogether, we analyzed 4,379 bp of sequences of both alleles of the pro alpha 1 (I) collagen (8,758 bp of allelic sequences) and 4,200 bp of sequences of both alleles of the pro alpha 2(I) collagen (8,400 bp of allelic) from each patient.

Adult↗

PubMed1996

Magnetic resonance imaging in the follow-up of patients after aortic root reconstruction.

Long-term survival after replacement of the aortic root with a composite graft is improving. Late deaths are in several cases due to complications related to the previous surgery or to pathologies of the remaining aorta. Regular follow-up of these patients is of paramount importance. The purpose of this study is to evaluate the reliability of magnetic resonance imaging (MRI) in such cases. Twenty-seven patients (9 dissections and 18 aneurysms) who had undergone replacement of the aortic root with a composite graft were studied 20 to 167 months after surgery using magnetic resonance imaging with a 1.5 Tesla magnet. The left-ventricular outflow tract, the mechanical valve function, the proximal part of the coronary arteries, the graft, and the remaining aorta could be examined. No aortic insufficiency, ectasy of the proximal part of the coronaries, or pseudoaneurysms were seen. A widening of the remaining ascending aorta was noted in 4 cases. A still open, dissected pipe was visualized in 7 patients. Our conclusions are that MRI provides excellent images of the thoracic and abdominal aorta following surgical repair. The examination is becoming cost-competitive. More import is its very low risk for the patient group considered here: since it is non-invasive and requires no contrast medium or X-ray exposure, examinations can be repeated as required.

Aortic Dissection↗

PubMed1996

Tetrasomy 18p de novo: parental origin and different mechanisms of formation.

We have used eight PCR-based DNA polymorphisms to determine the parental origin and mechanisms of formation in 9 patients with de novo nonmosaic tetrasomy 18p. The 9 patients, 4 girls and 5 boys, had clinical features characteristic of i(18p) syndrome. The supernumerary marker chromosome was identified by fluorescence in situ hybridization (FISH) analysis using centromeric probes and a flow-sorted 18p-specific library. The isochromosome was of maternal origin in all 9 cases. The formation of tetrasomy 18p cannot be explained by a single model. In 6 cases, meiosis II nondisjunction, followed by subsequent postzygotic misdivsion, and in 1 case postzygotic nondisjunction and postzygotic misdivision were the most likely mechanisms of formation. Alternative mechanisms are suggested in the remaining 2 cases.

Adolescent↗

PubMed1996

Replacement of the ascending aorta with composite valve grafts: long term results.

BACKGROUND AND AIMS OF THE STUDY: Long term survival after replacement of the aortic root is improving. The most common cause of late death is progression of disease in the remaining aorta (dissection or atherosclerosis). The purpose of this study was to review our clinical experience with composite graft replacement of the aortic root with special reference to long term results. MATERIALS AND METHODS: One hundred twenty-six patients (mean age: 53 years) with different pathologies of the ascending aorta underwent aortic root replacement with a composite-graft prosthesis over a 12-year period. Twenty-three patients had previously undergone cardiovascular surgery. The surgical technique included resection of the ascending aorta with the aortic valve and end-to-side anastomosis between full-thickness buttons of the aortic wall with the coronary ostia and the graft. One or more associated cardiovascular procedures were performed in 24 cases. Long term follow up to July 1995 is complete. Uni- and multivariate analysis were performed to identify risk-factors for early and late mortality and reoperation. RESULTS: Twenty-three patients died during the first 30 days (18%). Sixteen of them had aortic dissection. The most common cause of early death was heart failure. Twenty-three patients died during the follow up time with heart failure, again, being the most common cause of death. Thirteen late reoperations on the composite-graft or the remaining aorta were performed in 12 patients, six of whom had Marfan's syndrome. The 30-day mortality at reoperation was 30%. CONCLUSIONS: This surgical option offers good long term results with a five-year actuarial survival of 67% or 75% when the 30-day mortality is excluded. Careful follow up of patients with Marfan's syndrome and/or aortic dissection is mandatory to increase the long term survival.

Adolescent↗

PubMed1995

Brain biopterin metabolism in chronic experimental hepatic encephalopathy.

Chronic hepatic encephalopathy (HE) is a neuropsychiatric syndrome associated with a substantial increase in the brain L-tryptophan (L-TRP) level. Moreover, a supranormal L-TRP hydroxylating activity in the brain suggests an induced enzymatic process in chronic HE. GTP-cyclohydrolase I (GTPCHI) and tetrahydrobiopterin (BH4) are two major factors besides L-TRP that are involved in regulating the brain L-TRP hydroxylating activity. We therefore determined the GTPCHI activity, the total biopterin and the BH4 concentrations in the neocortex and mesencephalon-pons of portacaval shunted (PCS) rats. The encephalopathic component in PCS rats was accounted for by studying open field behaviour. The acute effects of a single parenteral L-TRP challenge were also evaluated. The basal GTPCHI activities in PCS rats were decreased bu 50% (p < 0.05) compared to controls in both investigated brain regions. No significant alterations in brain total biopterin or BH4 levels were present. The PCS rats exhibited a clearly reduced spontaneous locomotor activity. After the exogenous L-TRP load only a lower GTPCHI activity in the neocortex of PCS rats was recorded. We conclude that a perturbation in the brain biopterin metabolism is concomitantly present with behavioural abnormalities in the chronic PCS condition and that the acute effects of a superimposed L-TRP load do not aggravate these disturbances.

Animals↗

PubMed1995

The "90 degrees bent" two-stage venous cannula.

A 90 degree bent two-stage venous cannula for cardiopulmonary bypass is presented and discussed. Its main advantages, compared to similar straight ones, are that it is out of the way of the surgeon, by being placed under the right sternum and also that the venous return seems uninfluenced by displacement of the heart when operating on the posterior side of the heart. No major drawbacks for the cannula have been noticed so far.

Cardiac Catheterization↗

PubMed1995

Brain quinolinic acid in chronic experimental hepatic encephalopathy: effects of an exogenous ammonium acetate challenge.

Elevated brain concentrations of the neurotoxin and NMDA receptor agonist quinolinic acid (QUIN) have been demonstrated in portacaval-shunted (PCS) rats, a chronic hepatic encephalopathy (HE) model. Increased brain QUIN levels have also been shown in acute hyperammonemic rats. In the present study, the plasma and brain (neocortical) QUIN levels in chronic PCS rats were investigated. The study also included a single exogenous ammonium acetate (NH4Ac; 5.2 mmol/kg, i.p.) challenge to precipitate a reversible hepatic coma. Compared with sham-operated controls, chronic PCS rats exhibited decreased rather than increased plasma and brain QUIN levels. The plasma-to-brain QUIN ratio was not found to be altered. The NH4Ac administration induced coma in all of the PCS rats 20-25 min after the challenge, and this coma was resolved within 60-75 min. No relevant temporal relationship between changes in brain QUIN levels and the neurological status in the PCS rats was observed. Therefore, our results do not support the contention that increased brain QUIN levels per se are involved in the pathogenesis of HE.

Acetates↗

PubMed1995

Cytogenetic findings indicate heterogeneity in patients with blepharophimosis, epicanthus inversus, and developmental delay.

Three unrelated, mentally retarded boys with typical blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) were found to have chromosomal aberrations. One of them had a del(3)(p25), another patient had a de novo translocation t(2; 3), which after high resolution banding combined with chromosome painting was interpreted to be unbalanced with a loss of band q23. The third patient had a del(7)(q34). The phenotypes of the two patients with chromosome 3 related syndromes were similar, but the third also had genital malformations resembling the Smith-Lemli-Opitz syndrome. This patient had a palatal ridge, and a single mesial maxillary tooth suggesting the holoprosencephaly sequence, but CT scans of the brain were normal.

Abnormalities, Multiple↗

PubMed1995

Small intestinal absorption of polyethylene glycol 400 to 1,000 in the portacaval shunted rat.

Functional changes of the intestinal barrier that may occur after the creation of a portacaval shunt (PCS) were investigated. After chronic PCS in the rat, the intestinal absorption of and the jejunal permeability to the inert polymer marker polyethylene glycol (PEG) with molecular weight (Mw) ranging from 400 to 1,000 g/mol were investigated. The PEG mixture was orally fed to PCS and sham-operated rats, and urine was collected for 24 hours to obtain the urinary recovery of the different PEG polymers as a measure of intestinal absorption. To study the intestinal permeability, segments from the proximal small intestine were incubated in diffusion chambers with the PEG mixture on the mucosal side, and samples were withdrawn from the serosal side for analysis. The urinary recovery for the PEGs increased (P < .01) while the tissue permeability decreased (P < .001) in the PCS group rats in comparison with Sham-operated rats. The increased absorption in vivo was caused neither by altered renal clearance, nor by changed portal blood pressure. The decreased jejunal permeability in the PCS rats could be explained by a reduction of the mucosal area by shortening of the microvilli. This discrepancy indicates that changes in permeability and absorption may not be parallel during PCS. It is possible that these changes also may be affected by nutritional factors, drug therapy, as well as toxic substances.

Animals↗

PubMed1994

Monozygotic twins discordant for gastroschisis: case report and review of the literature of twins and familial occurrence of gastroschisis.

We describe a pair of monozygotic (MZ) female twins discordant for gastrochisis. To our knowledge, this is the first such case reported. The zygosity was verified by DNA analysis using highly polymorphic microsatellites. There was no family history of gastroschisis. During pregnancy there was no suspicion of any exposure responsible for the malformation. The number of twin cases described so far does not allow any conclusion as to hereditary factors in the cause of gastroschisis, but the number of families reported with familial gastroschisis suggests that the recurrence risk is higher than previously thought.

Abdominal Muscles↗

PubMed1994

Obstetrical and gynecological complications in fragile X carriers: a multicenter study.

We have conducted a multicenter obstetrical and gynecological survey of women in fragile X families. Included in the study were 131 gene carriers (39 with a full mutation and 92 with a premutation) and 109 noncarriers. Analysis indicated that higher numbers of fragile X gene carriers reported having irregular menses and other gynecological complications. As a group they also experienced cessation of menses prior to age 40 years at a significantly higher rate. The data appear to indicate that the FMR1 gene may play a role in the development and proliferation of oogonia.

Abortion, Spontaneous↗

PubMed1991

Brain tryptophan hydroxylation in the portacaval shunted rat: a hypothesis for the regulation of serotonin turnover in vivo.

Regional and whole-brain tryptophan-hydroxylating activity and serotonin turnover were investigated in portacaval shunted (PCS) rats using an in vivo decarboxylase inhibition assay. To saturate tryptophan hydroxylation with amino acid substrate, rats were administered a high dose of tryptophan 1 h prior to analysis of brain tryptophan, 5-hydroxytryptophan, serotonin, and 5-hydroxyindoleacetic acid. The analysis revealed, as expected, higher brain concentrations of tryptophan and 5-hydroxyindoles and increased serotonin synthesis rate in PCS rats as compared with shamoperated controls. Saturating levels of brain tryptophan were achieved in both PCS and sham animals after exogenous tryptophan administration. The tryptophan load resulted in increased brain serotonin turnover in all regions and in whole brain compared with rats that did not receive a tryptophan load. Tryptophan-loaded PCS rats showed increased brain serotonin turnover compared with tryptophan-loaded sham rats. Regionally, this supranormal tryptophan-hydroxylating activity was most pronounced in the mesencephalon-pons followed by the cortex. It is concluded that, at least in the PCS rat, brain tryptophan hydroxylation is an inducible process. Since it is known that brain tissue from PCS rats undergoes a redox shift toward a reduced state and that the essential cofactor tetrahydrobiopterin is active in tryptophan hydroxylation only when present in its reduced form, it is hypothesized that this is the reason for the supranormal tryptophan-hydroxylating activity displayed by the PCS rats. The hypothesis further suggests that alterations in tetrahydrobiopterin availability may serve as a mechanism by which brain tryptophan hydroxylation, and therefore serotonin turnover, can be regulated with high sensitivity in vivo.

5-Hydroxytryptophan↗

PubMed1990

A new internal mammary artery retractor.

A new retractor for asymmetric opening of the chest is presented. The instrument is mainly used for dissection of the internal mammary artery, but other applications are possible such as resection of large mediastinal tumors, or pulmonary resections through median sternotomy. The device is comprised of a standard retractor combined with a tilting mechanism which lifts one side of the chest (following median sternotomy) while depressing the other side, resulting in an asymmetric opening of the thoracic cavity. The retractor has been used routinely since late 1987. As of April 1990 it has been employed in more than 3000 operations, and has appeared to be safe and efficient.

Coronary Artery Bypass↗

PubMed1990

Pneumothorax in pregnancy.

Since 1957, only 15 cases of isolated spontaneous pneumothorax in pregnancy have to our knowledge been reported in the English literature. The treatment of pneumothorax in pregnancy is more difficult than in non-pregnant patients. A case is reported and therapy discussed.

Adult↗